All factory actions vary, but controlled-feed actions are normally more tolerant of rim-size variations than push-feed actions, partly because a lot of older CRF actions vary more. Even those made by FN, which was my point.
And of course we haven't even gotten into how much rim diameters vary on 6.5x55 brass. Cases can have what most people consider .30-06 diameter at the head, but the rims can vary independent of the case-head diameter.
